When to plant borage in Colorado
Colorado spans USDA zones 5b–7a, so the right time to plant borage shifts by weeks across the state. The window to sow seed directly outdoors runs from about April 14 in Grand Junction to June 21 in Edwards — below are local dates for 70 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Denver | 6a | May 4 | October 8 | May 4 – May 18 |
| Colorado Springs | 6a | May 3 | October 8 | May 3 – May 17 |
| Aurora | 6a | May 7 | October 8 | May 7 – May 21 |
| Fort Collins | 5b | May 2 | October 7 | May 2 – May 16 |
| Lakewood | 6a | May 3 | October 7 | May 3 – May 17 |
| Thornton | 6a | May 2 | October 11 | May 2 – May 16 |
| Arvada | 6a | May 5 | October 5 | May 5 – May 19 |
| Westminster | 6a | May 2 | October 11 | May 2 – May 16 |
Borage in Colorado: FAQ
When can I plant borage in Colorado?
Across Colorado, the time to direct-sow borage spans roughly April 14 in Grand Junction to June 21 in Edwards, each following that city's local frost dates.
Does the borage planting date vary across Colorado?
Yes. Colorado publishes 70 cities with their own frost dates, so the right borage planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does borage take to grow in Colorado?
Borage takes about 50–60 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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